Race for bigger turbines has prompted experts to urge growth slowdown and greater standardization
The rapid growth in size creates challenges for installation vessels, which soon become obsolete, and other parts of the supply chain including quaysides, which need strengthening
The 169 wind turbines spinning off the Yorkshire coast are an engineering feat: each eight-megawatt model erected by Danish developer Ørsted can power a home for 24 hours with a single rotation of its 81-metre turbine blades.
Dozens of miles north, rival wind farm developer SSE is already upping the ante with its newest turbines, where a single rotation of the 107-metre blade can power a home for two days.
The jump in turbine size in the offshore wind industry, where blades can reach higher than New York’s Rockefeller Center and provide electricity for millions of homes, reflects the fierce race for scale over the past decade or more.
The rapid pace of evolution spurred on by wind farm developers and turbine makers has helped push down costs and proved that the industry can play an important part in decarbonising the energy system. But critics fear the race may now be starting to do more harm than good, as supply chains struggle to catch up and questions over technical risk and profitability for turbine makers arise.
“The acceleration in the cycles for developing new wind turbine models in recent years has not been helpful,” said Christoph Zipf, a spokesperson for trade group WindEurope. “It needs to slow down.”
Many industry executives want an end to the era of turbine growth with a period of standardization of turbine models seen as the best way to help developers meet rapid growth targets.
While a cap on turbine size has also been discussed seriously within the industry, many developers still find it hard to resist the lure of the higher efficiencies touted. Turbine producers also face continuing competition for larger machines, especially from Chinese rivals.
From the early models in the 1990s of less than one megawatt, turbines are now being developed with a capacity of 18MW or more, with blades longer than football pitches supported by towers rising more than 100 metres above the water’s surface.
Getting more electricity from each turbine has helped push down the costs of energy from wind by 60 per cent during the decade to 2021, according to the International Renewable Energy Agency.
The rapid pace of development brings its challenges, however, for example for makers of the vessels installing the turbines as well as other parts of the supply chain that need to adapt to the huge increases in size and weight. “You are [now] talking about nacelles [part of the turbine] weighing 800 to 1,000 tonnes,” said Anders Nielsen, chief technology officer at leading turbine manufacturer Vestas. “You need to reinforce the quayside [to cope].”
A report from consultants Wood Mackenzie this month said that about half of the world’s installation vessels are set to retire because they are not designed to cope with the newer turbine models, with about $13bn of investment needed for replacements. But vessel owners have already been burned by investing heavily in new models only to find they were quickly outgrown, said Torgeir Ramstad, managing director in the installation division at offshore vessel owner Cyan Renewables. “We [Cyan] will only now build on the basis of long-term contracts from developers,” he said.
The rapid pace of development means models are being introduced before the performance of existing models has been observed over the long term, raising questions about whether potential problems are understood.
“I don’t know of any other industry that’s pushed ahead at this pace in terms of bringing new models to market before there’s any real service experience on the previous levels,” said Professor Simon Hogg, who holds the Ørsted chair in renewable energy at Durham University. “That has put a lot of risk into the industry.”
Renewable energy insurer GCube said in a report in May that machines larger than 8MW were reporting problems more quickly than their smaller counterparts. Meanwhile, finances in the industry are under strain. Turbine manufacturers have borne steep losses over the past few years as they try to churn out new models while keeping prices down, and grapple with warranty provisions.
Developers are now also under pressure from inflation and high interest rates. Swedish developer Vattenfall in July halted a new project in the North Sea, while Iberdrola and Shell are also exiting agreements in the US.
Slowing down the development of new turbine models and instead focusing on standardizing existing models may now be the best way for the industry to grow and meet stretching clean energy targets, some believe.
Jochen Eickholt, chief executive of turbine maker Siemens Gamesa, said that while size increase was technically possible, “much larger turbines would need a proper infrastructure that is not there yet, including ports and vessels”.
Siemens Gamesa is battling technical problems with its latest onshore wind turbines as well as challenges ramping up offshore wind. “The priority should be to guarantee a sustainable and profitable future for the business while delivering the surging targets around the world,” Eickholt said.
Ben Backwell, chief executive of the Global Wind Energy Council, an industry body, believes that the industry should now roll out existing models at industrial scale, saying this would allow companies to take advantage of the investment in models so far. “It is also important that projects can benefit from investments in installation equipment and infrastructure such as vessels and cranes without these becoming constantly obsolete due to continual increases in turbine size,” he said.
Focusing on existing models is easier said than done, however, given the fierce competition in the market. “If General Electric [comes out with a larger model], Siemens Gamesa will immediately counter that. And then Vestas will be under pressure to counter that,” said Shashi Barla, head of research for renewable energy at the consultancy Brinckmann.
A race for size among Chinese manufacturers adds to that competitive pressure. Chinese offshore turbine manufacturers could start to make more significant inroads into the western offshore market as costs in the US and Europe rise, said Barla.
Cyan’s Ramstad believes a cap on turbine size would ensure standardization, preventing the market from overshooting. “We desperately need this electricity, and the way to build fast is to industrialize, streamline, standardize,” he said.
Wood Mackenzie said in its report that a temporary cap, lasting at least 10 years, would “give suppliers and investors confidence in their new investment”.
“Ultimately the most important factor is not the size of the cap but that a cap is imposed,” it added. Many players in the sector do not back a cap, with some concerned that it could have unintended consequences.
“What we need to see is progressive evolution rather than revolution and avoid putting measures in place that could potentially stifle innovation,” said Rob Anderson, project director for Vattenfall’s wind projects off Norfolk.
Iberdrola, one of the world’s largest wind farm developers, backs a slowdown in new models although it does not believe a cap is necessary. With improved profit margins in the future, “we are confident that the industry will experience a new momentum and bigger sizes will be developed”, it said.
Nielsen at Vestas is of a similar view, emphasizing the need for responsible development. “The only way that can actually attend to the market demand is to slow down the growth of turbines,” he said, adding: “This industry needs to mature and everyone has to make money in the supply chain to make it last.”
Source: Financial Times